Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Election/Restrictions
Applicant’s election without traverse of Invention 1 (claims 1-9, 12, and 13) in the reply filed on 25 August 2026 is acknowledged. Claims 15-23 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention, there being no allowable generic or linking claim.
Drawings
The drawings are objected to as failing to comply with 37 CFR 1.84(p)(5) because they do not include the following reference sign(s) mentioned in the description: 100, 102, 110, 120, 122, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 160, 170, 172, 180, 300, 310, 320, 330, 400, 402, 404, 410, 470, 472, 474, 500, 510, 590, 592, 594, 600, 610, and 620. See [0075]-[0099] and [0103]-[0105]. The drawing sheets as filed do not include any reference signs.
Applicant is directed to WO 2025/035037, published from PCT/US2024/041576, which claims the benefit of the same provisional application as the present application (Application No. 63/518,727). The drawing sheets of WO 2025/035037 correspond to the drawing sheets of the present application and bear reference signs for all but one of the signs listed above. Reference sign 172, recited in [0078] as designating the vertical drive mechanism and located in FIG. 2C, does not appear on the corresponding sheet of WO 2025/035037. Any replacement sheets submitted in reply to this objection should include reference sign 172.
Corrected drawing sheets in compliance with 37 CFR 1.121(d) are required in reply to the Office action to avoid abandonment of the application. Any amended replacement drawing sheet should include all of the figures appearing on the immediate prior version of the sheet, even if only one figure is being amended. Each drawing sheet submitted after the filing date of an application must be labeled in the top margin as either “Replacement Sheet” or “New Sheet” pursuant to 37 CFR 1.121(d). If the changes are not accepted by the examiner, the applicant will be notified and informed of any required corrective action in the next Office action. The objection to the drawings will not be held in abeyance.
Specification
The disclosure is objected to because of the following informalities:
In [0061], “spatially confirmed” should be replaced with “spatially confined”. See [0087].
In [0061], “an included angle at the distal tool tip of at 20 degrees or less” should be replaced with “an included angle at the distal tool tip of 20 degrees or less”.
In [0080], “drives rotation of a toothed gear attached to the rotational axle 138” should be replaced with “drives rotation of a toothed gear attached to the tilting axle 138”. Reference sign 138 designates the tilting axle. See [0080] and [0091].
In [0086], “the duct can carry liquid coolant to cool the heatsink 320” should be replaced with “the duct can carry liquid coolant to cool the heatsink 330”. Reference sign 320 designates the tool tip and reference sign 330 designates the heatsink. See [0086].
In [0087], the sentence ending “between the print head and the printed part and/or build platform..” contains a duplicated period.
In [0090], “a rotatable print bet” should be replaced with “a rotatable print bed”.
In [0092], “The worm gear 144 engages a gear 146 connected to a tilting axle 148” should be replaced with “The worm gear 144 engages a gear 146 connected to a rotational axle 148”. Reference sign 148 designates the rotational axle. See [0079].
In [0100], “Periodic cleaning of the tool tip during user” should be replaced with “Periodic cleaning of the tool tip during use”.
In [0100], “This method of tool tip cleaning is can be particularly advantageous” should be replaced with “This method of tool tip cleaning can be particularly advantageous”.
In [0117], “the interface is made mode resistant to fracture” should be replaced with “the interface is made more resistant to fracture”.
In [0124], “material and or weight savings” should be replaced with “material and/or weight savings”.
Appropriate correction is required.
Claim Objections
Claims 8 and 9 are objected to because of the following informalities:
In claim 8, “as a model is constructed on the platform” should be replaced with “as a model is constructed on the build platform” for consistency with claim 1.
In claim 8, “due to the construction of a model on the build platform” should be replaced with “due to the construction of the model on the build platform”.
In claim 9, “an included angle at the distal tool tip of at 20 degrees or less” should be replaced with “an included angle at the distal tool tip of 20 degrees or less”.
In claim 9, “the print head is further spatially confirmed within a cylindrical boundary volume” should be replaced with “the print head is further spatially confined within a cylindrical boundary volume” for consistency with the recitation earlier in claim 9 of the print head being “spatially confined” within the conical boundary volume, and with [0087].
Appropriate correction is required.
Claim Interpretation
The claim limitations “a rotating drive mechanism” and “a tilting drive mechanism” in claim 1 are not being interpreted under 35 U.S.C. 112(f) because persons of ordinary skill in the art reading the specification would understand the term “drive mechanism” to have a sufficiently definite meaning as the name for structure. See MPEP 2181(I)(A).
Claim 9 recites that the print head is spatially confined within a conical boundary volume originating at a distal tool tip of the print head and defined by an included angle at the distal tool tip of 20 degrees or less, and is further spatially confined within a cylindrical boundary volume coaxial with a longitudinal axis of the print head passing through the distal tool tip and having a diameter of 20 mm or less. These limitations are being interpreted as requiring that the external envelope of the print head lie within both of the recited volumes, and therefore as requiring at least that no portion of the print head extend more than 10 mm from the longitudinal axis of the print head at any location along the print head. The recited boundary volumes are not themselves structural elements of the claimed printer.
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 1, 2, 7, and 13 are rejected under 35 U.S.C. 103 as being unpatentable over US 2016/0067740 A1 (“Voris”) in view of US 2018/0345563 A1 (“Sternå”).
Regarding claim 1, Voris discloses a five-axis 3-D printer (the 3D printer 700; see Figures 7-9 and [0052]-[0056]), comprising:
a tilting-rotatable bed (the assembly 760; see [0053]) comprising:
a build platform (the build plate 770 having an upper print surface 772; see [0053] and [0054]);
a rotating drive mechanism operably connected to the build platform to command a rotational position of the build platform (the yaw motor or actuator 768, coupled to the pivotal mount assembly 764 and/or the build plate 770 and operable to cause the build plate 770 to yaw; see [0055]); and
a tilting drive mechanism operably connected to the build platform to command a tilt position of the build platform (the tilt motor 766, which rotates the build plate 770 as shown by arrows 868 about the tilt axis 767 extending through the assembly 764 to set the print angle, β, of the upper surface 772; see Figure 8 and [0055]); and
a print head positioned above the build platform (the print head 730, supported above the build plate 770 by the print head support assembly 720; see Figure 7 and [0052]), at least one of the build platform and print head being movable to command a position of the print head relative to the build platform along three orthogonal axes (the assembly 720 positions the print head 730 to differing X-Y coordinates, and the vertical positioning devices 861 coupled with the support frame 710 move the base 762 carrying the build plate 770 up and down along a Z-axis as shown by arrows 863; see Figure 8 and [0052]-[0053]).
The five axes recited in the preamble are accordingly present in Voris as the X-Y motion of the print head support assembly 720, the Z motion of the vertical positioning devices 861, the tilt of the build plate 770 about the tilt axis 767, and the rotation of the build plate 770 about its center vertical axis. Voris further specifies that in the printer 700 the print head 730 is not raised and lowered, and that the movements 863 are used to move the print surface 772 and the in-process 3D object relative to the print nozzle 734 to print the object’s layers, so the Z motion of the base 762 is not an optional feature of the printer 700 but the means by which it prints successive layers. See [0053].
Voris attributes rotation of the build plate 770 about its center vertical axis both to a print controller and to the yaw motor 768. In [0054], the build plate 770 is described as a rotating or rotatable disc that can be selectively rotated by a print controller, as shown with arrow 774, about a center vertical axis to position the 3D object 750 relative to the print nozzle 734. In [0055], the yaw motor or actuator 768 is described as coupled to the assembly 764 and/or the build plate 770 and operable by a print controller to cause the build plate 770 to selectively yaw, in order to orient the upper surface 772 and the 3D object 750 upon it relative to the print nozzle 734. Yaw is rotation about a vertical axis; the two passages recite the same axis and the same purpose; and Voris identifies no other actuator by which the rotation shown at 774 is produced. Voris confirms that the build plate rotates about its own vertical axis at claim 20, which recites that the upper surface of the build plate is rotatable about a central axis to reposition the 3D object relative to the print nozzle. The yaw motor 768 is therefore the drive mechanism operably connected to the build plate 770 that commands its rotational position.
Voris does not disclose at least one of the build platform and print head comprising a load cell.
Sternå is directed to a 3D printer having a print bed 2 and an actuating toolhead 3 carrying an extrusion element 4, in which force sensing between the toolhead and the print bed is used to characterize the print surface and to control the printing process. See [0029]-[0036]. Sternå discloses at least one sensor 5a-5d arranged to sense a force applied to the print bed by the extrusion element of the actuating toolhead, or vice versa, and states that the at least one sensor may comprise a load cell, the load cell comprising a transducer arranged to generate an electrical signal directly proportional to the force being measured, and being for example a strain gauge load cell or a piezo-electric load cell. See [0036]. The sensor may be arranged at the print bed, where it comprises for example a scale (the sensor 5a; see [0043]), or mounted at the actuating toolhead, such as at an extrusion end of the extrusion element (the sensor 5b; see [0044]). Sternå further discloses a control element 7 arranged to detect when the sensed force exceeds a predetermined value and to record a position of the print bed or extrusion element related to that detection, the exceeding of the predetermined value indicating that the extrusion element 4 is in contact with the print bed 2. See [0039] and [0040]. By recording a plurality of such positions, illustrated as positions a, b and c in Figures 1b and 1c, the shape and/or orientation of the print bed 2 can be determined prior to starting the printing process, and the print bed can then be adjusted based on the measurements and/or the printing process can be adjusted to take the resulting model of the print surface into consideration. See [0040].
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have provided the build plate 770 or the print head 730 of Voris with a load cell, as taught by Sternå, in order to sense contact between the print head and the build plate, so as to determine the shape and orientation of the print surface relative to the print head before printing begins and to adjust the printing process accordingly. See Sternå at [0039] and [0040]. The need that Sternå identifies is present in Voris to a greater degree than in Sternå itself: Voris defines the tilt and rotational orientation of the build plate 770 for each print location of each print layer and transmits control signals to the motors 766 and 768 to reorient the plate accordingly (see [0056]), so the position and attitude of the print surface 772 relative to the print nozzle 734 changes continuously throughout the build, and Voris discloses no means of measuring it. This constitutes applying a known technique to a known device ready for improvement to yield predictable results. See MPEP 2143(I)(D).
Regarding claim 2, modified Voris discloses wherein the build platform is supported by an underlying support bracket tiltable by the tilting drive mechanism (the pivotal mount assembly, or tilt mount/bracket, 764, which pivotally couples the build plate 770 to the base 762, and about the tilt axis 767 of which the tilt motor 766 rotates the plate 770; see Figure 7 and [0054]-[0055]), and wherein the rotating drive mechanism is supported by the underlying support bracket (the yaw motor or actuator 768, which is coupled to the assembly 764 and/or the build plate 770; see Figure 7 and [0055]).
Figure 7 shows the assembly 764 as a yoke rising from the base 762 and carrying the build plate 770, with both the tilt motor 766 and the yaw motor 768 mounted at the yoke below the plate.
Regarding claim 7, modified Voris discloses wherein the printer is configured to perform a calibration process to detect a tilt position of the build platform by detecting contact between the print head and the build platform at a plurality of tilt positions of the build platform.
Sternå’s control element 7 detects when the sensed force exceeds a predetermined value, the exceeding of that value indicating that the extrusion element 4 is in contact with the print bed 2, and records a position of the print bed or extrusion element related to that detection. See [0039] and [0040]. Sternå determines the z-position of the extrusion element in relation to the print bed for a plurality of predetermined positions in an xy-plane perpendicular to the z direction, and determines a tilt angle and orientation of the print bed based on the plurality of determined positions. See [0054]. The recorded positions are stored as calibration parameter values for use in subsequent control of printing, Sternå stating that calibration is thereby provided. See [0055]. Sternå further discloses that the control element may record the angular position of a motor axis of the motor arrangement as the recorded position of the print bed. See [0053].
In Sternå, the tilt of the print bed 2 is a fixed and unintended condition, arising from improper alignment, damage, or manufacturing imperfections, and the contact detection is accordingly performed at a plurality of positions in the xy-plane while the bed remains in a single attitude. See [0040]. Sternå does not disclose detecting contact at a plurality of tilt positions of the build platform.
In modified Voris the tilt of the build plate 770 is neither fixed nor unintended. The tilt motor 766 rotates the plate 770 about the tilt axis 767 to set the print angle, β, of the upper surface 772, and Voris defines that angle for each print location of each print layer and transmits control signals to the motor 766 to move the plate accordingly. See [0055] and [0056]. A calibration performed at a single tilt position would yield calibration parameter values corresponding to one of the many print angles that Voris commands, and would provide no information about the relationship between a commanded tilt and the resulting attitude of the plate elsewhere in its range of travel.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have performed the contact-based calibration of Sternå at a plurality of the tilt positions to which Voris commands the build plate 770, and thereby to detect the tilt position of the plate, in order to obtain calibration parameter values valid across the range of print angles over which Voris tilts the plate rather than at a single angle. This constitutes applying a known technique to a known device ready for improvement to yield predictable results. See MPEP 2143(I)(D).
Regarding claim 13, modified Voris discloses wherein the print head is moveable to command a position of the print head relative to the build platform outside of a working volume overlying the tilting-rotatable bed and enclosed by vertical columns of the printer.
Claim 13 recites two modifiers on a single working volume: the volume overlies the tilting-rotatable bed, and it is enclosed by vertical columns of the printer. The working volume is accordingly the volume overlying the bed, and “enclosed by” carries its ordinary meaning of surrounded by, or bounded on its sides by. Vertical columns are discrete members rather than a continuous surface. If “enclosed by” required the enclosing structure’s boundary to coincide with the boundary of the volume enclosed, discrete columns could never enclose anything and the limitation would be null. The phrase therefore requires that the bed-overlying working volume lie within the region defined by the columns, in the sense that a courtyard is enclosed by the buildings around it without being flush against them.
Voris discloses a housing or support frame 710 configured as an open box with vertical corner members, a print head support assembly 720 in the form of a horizontal rail spanning the width of the frame, and a build plate 770 in the form of a disc occupying a substantially smaller central footprint within the frame. See Figure 7 and [0052]-[0054]. The working volume overlying the build plate 770 lies within the region defined by the vertical members of the frame 710. Because the assembly 720 spans the full width of the frame while the build plate 770 occupies only a small central portion of it, the print head 730 travelling along the assembly 720 is positioned beyond the lateral edges of the build plate 770 and therefore outside the working volume overlying it. See Figure 7.
Claims 3 and 4 are rejected under 35 U.S.C. 103 as being unpatentable over Voris in view of Sternå, as applied to claim 1 above, and further in view of US 2017/0259502 A1 (“Chapiro”).
Regarding claims 3 and 4, modified Voris does not disclose wherein the rotating drive mechanism is capable of infinitely rotating the build platform, or wherein the build platform is supplied with electrical power via an electrical slip ring.
Chapiro is directed to a five-axis additive manufacturing device for printing continuous fiber reinforced parts, in which three sets of rails 40a, 40b, 40c provide movement of the nozzle 10 in the X, Y, and Z directions while the build plate 42 and the nozzle 10 rotate about axes designated A and B respectively. See [0104]. Chapiro discloses an interface between spring-loaded contacts and slip rings, comprising a plurality of slip rings 52, a plurality of springs 54, a plurality of rocker arms 56, a plurality of electrical contacts 58, a housing 60, a housing cap 62, and a central shaft 64. See Figure 16A and [0162]. The slip rings are axially aligned with the central shaft and are stacked and spaced along it within the housing and housing cap; the electrical contacts are each adjacent to one of the slip rings; and the springs are attached to the housing at one end and to the rocker arms at the other, the opposite ends of the rocker arms being held on a pin 66 between the housing and the housing cap. See [0163]. Chapiro states that this interface allows the transfer of energy to a continuously rotating build plate, that each spring and rocker enables continuous contact of the electrical contacts with the slip rings to allow uninterrupted electrical energy transfer, and that this enables the central shaft to continuously rotate, which enables multiple useful printing operations such as winding. See [0164]. The build plate is attached to the slip ring assembly by being fixed to the main shaft 64, and cables 68 pass to the build plate assembly, which comprises a top layer 72, a heating layer 74, a thick insulating layer 76, and a final insulating layer 78. See Figure 16B and [0165]-[0166]. Chapiro states that in operation this system enables effective heating of the build plate in conjunction with continuous rotation. See [0167].
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have provided the build plate 770 of modified Voris with the slip ring interface of Chapiro, so as to supply electrical power to the build plate and to permit the rotating drive mechanism to rotate the plate continuously and without limit. Voris rotates the build plate 770 about its center vertical axis to position the 3D object 750 relative to the print nozzle 734 (see [0054] and [0055]) but does not disclose how electrical power is delivered to the plate or whether its rotation is limited. Chapiro identifies both the problem and the benefit: a wired connection to a rotating build plate constrains its rotation, and the slip ring interface allows uninterrupted energy transfer and therefore continuous rotation, which enables printing operations such as winding. See [0164]. Chapiro further establishes the benefit of supplying power to the plate, its heating layer 74 requiring electrical energy while the plate rotates. See [0166] and [0167].
Claim 5 is rejected under 35 U.S.C. 103 as being unpatentable over Voris in view of Sternå, as applied to claim 1 above, and further in view of US 2017/0165917 A1 (“McKiel”).
Regarding claim 5, modified Voris does not disclose wherein the build platform is operably connected to at least one of the rotating drive mechanism or the tilting drive mechanism via a worm gear.
McKiel is directed to additive manufacturing systems, and discloses at Figure 11 an alternative system 1100 in which rotational motion is applied to the build plate. See [0110]. The build plate platform of the system 1100 includes a build plate 1120, rotary shaft bearings for the build plate, a worm gear assembly comprising a worm 1162 and a worm wheel 1164, and a build plate rotation motor 1160. See [0117]. In an alternative arrangement, a common shaft 1172 is coupled to an elevation motor 1170 through a thrust bearing and to a stationary motor 1160 and worm 1162, the shaft 1172 being free to slide vertically through the worm wheel 1164 yet coupled to it by a key or splines so that the worm wheel can apply torque to turn the build plate 1120 through the shaft 1172, the thrust bearing permitting the elevation motor to drive the shaft vertically while the shaft rotates freely under control of the worm wheel. McKiel states that the motor 1160 and the motor 1170 independently control the rotation and the elevation of the build plate respectively. See [0117].
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have connected the build plate 770 of modified Voris to the rotating drive mechanism via a worm gear assembly as disclosed by McKiel. Voris discloses that the build plate 770 is rotated about its center vertical axis by a motor, the yaw motor or actuator 768, which is coupled to the assembly 764 and/or the build plate 770 and operable by a print controller, but does not disclose the means by which the motor is coupled to the plate. See [0054] and [0055]. McKiel discloses a worm gear assembly as one means of coupling a rotation motor to a build plate so as to turn it. See [0117]. It would have been obvious to use the worm gear assembly of McKiel to accomplish the rotation desired by Voris, since McKiel demonstrates that such an arrangement is suitable for that task. Claim 5 recites the worm gear on at least one of the rotating drive mechanism or the tilting drive mechanism, so the rotating branch alone satisfies the limitation.
Claim 9 is rejected under 35 U.S.C. 103 as being unpatentable over Voris in view of Sternå, as applied to claim 1 above, and further in view of US 2017/0072632 A1 (“Page”).
Regarding claim 9, and in view of the claim objections set forth above, claim 9 is examined as reciting that the print head is spatially confined within a cylindrical boundary volume, and as reciting an included angle at the distal tool tip of 20 degrees or less.
Modified Voris does not disclose wherein the print head is spatially confined within a conical boundary volume originating at a distal tool tip and defined by an included angle at the distal tool tip of 20 degrees or less, or wherein the print head is further spatially confined within a cylindrical boundary volume coaxial with a longitudinal axis of the print head passing through the distal tool tip and having a diameter of 20 mm or less.
Page is directed to the design of a narrow-profile hot end for a fused filament fabrication three-dimensional printer. Page discloses that the hot end components, including the nozzle 138, a heater, a temperature sensor, a material delivery channel, a heat sink, and the cooling delivery system, are contained within a volume 140 defined with reference to a nozzle target point 142 and shown in cross section as a cone. See Figure 1B and [0034] and [0039]. The volume 140 is bounded by a total included angle 148 defined with respect to the nozzle target point 142, and Page identifies a cone 147 whose apex is the center of the aperture 144 at the most downstream point in the nozzle 138. See [0035]. The total included angle 148 can range from 10 to 60 degrees inclusive, from 10 to 45 degrees inclusive, from 30 to 60 degrees inclusive, from 30 to 45 degrees inclusive, and from 20 to 45 degrees inclusive. See [0036]. Page teaches that the total included angle 148 can be adjusted based on how close the upstream components need to come to the nozzle 138 and based on how narrow a profile the hot end needs for the planned application, and that the hot end components are designed to fit within the volume 140 in view of how much plunge capability is desired. See [0037] and [0039]. Page explains that the narrow profile allows the hot end to extrude material at a deeper part of a steep side 222 of an object without causing the upstream components of the hot end to crash into a higher part of that side, thereby enabling the use of more types of three-dimensional tool paths. See Figure 2A and [0043]. Page further discloses that the volume containing the hot end components need not be a cone, a faceted cone being used in the delta printer 160 of Figure 1C, and that other types of volumes can also be used depending on the specific three-dimensional printing application. See [0040].
Regarding the conical boundary volume, Page’s disclosed ranges for the total included angle 148 encompass values of 20 degrees or less, the range of 10 to 45 degrees inclusive extending from 10 degrees up to and beyond 20 degrees, and 20 degrees being an expressly disclosed endpoint of the range of 20 to 45 degrees inclusive. Where the claimed range overlaps or lies inside a range disclosed by the prior art, a prima facie case of obviousness exists. See MPEP 2144.05(I).
Regarding the cylindrical boundary volume, Page does not state a diameter. Page does, however, recognize the transverse dimension of the bounding volume as a variable that determines the printer’s ability to reach into deep or steeply pitched regions of a part, teaching that the angle bounding the volume is adjusted according to how narrow a profile the hot end needs for the planned application and how much plunge capability is desired. See [0037], [0039], and [0043]. The transverse dimension of the boundary volume within which the print head is confined is therefore a result-effective variable, and where the general conditions of a claim are disclosed in the prior art it is not inventive to discover the optimum or workable ranges by routine experimentation. See MPEP 2144.05(II)(A) and (II)(B) and In re Antonie.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have configured the print head 730 of modified Voris to be spatially confined within a conical boundary volume originating at the distal tool tip and defined by an included angle of 20 degrees or less, and further within a cylindrical boundary volume coaxial with the longitudinal axis of the print head and having a diameter of 20 mm or less, as suggested by Page, in order to obtain the plunge capability and the access to steeply pitched surfaces that Page attributes to a narrow hot end profile. Page’s teaching that the volume containing the hot end components need not be a cone and that other types of volumes may be used depending on the application further supports capping the upper portion of the volume with a cylindrical surface. See [0040].
Claim 9 requires the print head to satisfy both boundary volumes, so the operative envelope is their intersection: the cone limits the envelope near the distal tool tip, and the cylinder limits it above the height at which a 20 degree cone would exceed 20 mm in diameter, which occurs at approximately 57 mm from the tip. This is consistent with applicant’s own description of the adjoining cylindrical volume at [0088] of the specification.
Claim 12 is rejected under 35 U.S.C. 103 as being unpatentable over Voris in view of Sternå, as applied to claim 1 above, and further in view of US 2019/0262986 A1 (“Newell”).
Regarding claim 12, modified Voris does not disclose wherein the print head further comprises at least one light source to pre-heat a deposition area.
Newell is directed to extrusion-based additive manufacturing using thermal management along the tool path. Newell discloses localized pre-heating of the tool path ahead of the print head, performed with a pre-heater 120 that in one embodiment is positioned on, ahead, or near the print head 104 to provide local pre-heating of the tool path on a previously printed portion of the 3D part ahead of the print head. See [0049]. Newell states that such localized pre-heating may be performed using suitable pre-heating apparatus including, by way of example and not by limitation, laser pre-heating, hot gas pre-heating, induction pre-heating, microwave pre-heating, and ultrasonic pre-heating. See [0049]. Newell explains that pre-heating serves to heat the intermediate part surface on which the new material is to be printed sufficiently for good adhesion of material to existing material, that part strength can be manipulated with such multi-layer heating treatments, and that the use of a localized pre-heating operation enables elimination of a controlled thermal chamber environment or a reduction in the temperature of the build environment. See [0049].
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have provided the print head 730 of modified Voris with a laser pre-heater positioned on the print head, as taught by Newell, in order to locally pre-heat the previously printed material on which new material is to be deposited and thereby improve adhesion of the new material to the existing material, and to permit elimination or reduction of a controlled thermal chamber environment. See Newell at [0049]. A laser is a light source.
Allowable Subject Matter
Claims 6 and 8 are objected to as being dependent upon a rejected base claim but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
The following is a statement of reasons for the indication of allowable subject matter.
Claim 6 requires the printer to be configured to perform a calibration process that detects a rotational position of the build platform by detecting contact between the print head and the build platform at a plurality of rotational positions of the build platform. No reference of record discloses or suggests detecting a rotational position of a build platform in this manner.
Sternå is the closest prior art directed to contact-based calibration. Sternå detects contact by sensing when the force applied between the extrusion element 4 and the print bed 2 exceeds a predetermined value, and records a position of the print bed or extrusion element related to that detection. See [0039]. Sternå determines the z-position of the extrusion element in relation to the print bed for a plurality of predetermined positions in an xy-plane and determines from those positions a tilt angle and orientation of the print bed, storing the recorded positions as calibration parameter values. See [0054] and [0055]. Every quantity that Sternå recovers is a z-displacement, or a quantity derived from z-displacements measured at differing lateral positions. Sternå’s print bed does not rotate about a vertical axis, and rotating a substantially flat and level print bed about a vertical axis does not change the height of the bed surface at a fixed probe location. Repeating Sternå’s contact detection at a plurality of rotational positions of such a platform would therefore return substantially the same measurement at each rotational position and would not detect a rotational position of the platform. Neither Sternå nor any other reference of record supplies the asymmetry in the platform, or the geometric relationship, that would make such a measurement informative, and one of ordinary skill in the art accordingly would have had no reason to perform the calibration at a plurality of rotational positions.
US 2016/0257068 A1 (“Albert”), which is the closest prior art disclosing contact detection between a nozzle and a rotatable platform, does not remedy this deficiency. Albert discloses a polar coordinate printer having a platform 445 rotated by a platform turning mechanism 455, and a contact 450 positioned on the platform and arranged to generate a signal when it is touched by the nozzle 260. See [0067] and [0070]. Albert places the top surface of the contact at the exact center of the circular top surface of the platform, which is the one location at which rotation of the platform produces no change in the position of the contact relative to the nozzle, and Albert uses that arrangement to inform the control system that the nozzle is at the exact center of the platform, which Albert identifies as useful for a printer operating in polar coordinates. See [0068] and [0129]. Albert’s refinement of the measurement is a second touching of the same contact with a slower approach of the platform, not a touching at a differing rotational position. See [0130]. Albert therefore uses contact detection to locate the center of the platform, not to detect a rotational position of it.
Voris, which does rotate its build plate 770 about a center vertical axis, discloses no force sensor, no contact detection, and no calibration process of any kind.
Claim 8 requires the printer to be configured to perform a compensation process to compensate for an expected deflection of the build platform as a model is constructed on the platform, the process comprising probing the build platform at one or more locations while measuring a force-deflection curve, and adjusting a toolpath of a printing process based on the measured force-deflection curve to compensate for deflection of the build platform due to the construction of a model on the build platform during the printing process. No reference of record closes the loop that this claim recites, namely measuring a force-deflection curve of the build platform by probing it, deriving the platform’s compliance from that curve, and using the result to adjust a toolpath so as to compensate for the deflection that the platform will undergo as the mass of the model accumulates during the print.
Sternå is the closest prior art, and it supplies the sensing hardware, disclosing force sensors including load cells arranged at the print bed and at the actuating toolhead. See [0036], [0043], and [0044]. Each of Sternå’s uses of that hardware nonetheless falls short of the recited compensation process. Sternå’s probing at a plurality of positions determines the shape and orientation of the print bed prior to starting the printing process (see [0040] and [0054]), which characterizes the geometry of the bed rather than its stiffness, and which is performed once before the print rather than to predict deflection occurring during the print. Sternå does pair an applied force with a resulting deformation, describing a deposit material as soft enough to deform by Δz under a first force from the extrusion element or stiff enough to resist deformation under that force (see [0041]), but the deformability there is that of the deposited material, not a measured force-deflection curve of the build platform. Sternå also measures accumulating mass on the bed, the added mass manifesting as an increased force on the print bed measured by a sensor 5a comprising a scale, the measured force being proportional to a load on the bed which is in turn proportional to the total mass of deposit material deposited (see [0056]), but that measurement is used to verify that material is being deposited as expected and to detect a clogged or broken extrusion element or exhausted deposit material, not to compensate a toolpath for load-induced deflection of the platform. Sternå thus measures force, and separately measures geometry, but never derives the compliance of the build platform from the relationship between the two.
US 2014/0117575 A1 (“Kemperle”) is the second-closest prior art on this point. Kemperle stores surface contact forces along with corresponding x-y positions on the surface and uses them later during fabrication to compensate for the measured irregularities (see [0054]), and generates a control signal in response to a current contact force that changes the feed rate of build material or varies the Z-axis position of the extruder relative to the build platform in order to maintain relatively steady material deposition while adjusting to surface irregularities (see [0063]). What Kemperle compensates for is irregularity in the surface as found, such as warping, dents, scratches, or skew (see [0054]), not deflection induced in the platform by the accumulating weight of the model, and Kemperle measures no force-deflection curve.
Neither reference identifies load-induced deflection of the build platform during a print as a problem to be solved, and one of ordinary skill in the art accordingly would have had no reason to modify either one to measure the platform’s force-deflection response and to predict from it the deflection that the platform will undergo as the model’s mass accumulates.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
US 2021/0206116 A1 (“Ji”) is cited as being of interest for its disclosure of a strain sensor for a three-dimensional printing head assembly, comprising a fixing plate 10 having a first supporting part 11 and a second supporting part 12 that is flexibly connected to and perpendicular to the first supporting part, the second supporting part being disposed in a cutout portion of the fixing plate and carrying a resistance strain gauge 13 connected to it by adhesion or welding, the fixing plate being made of metal and preferably of spring steel so as to be capable of flexible deformation. See Figure 1 and [0025]-[0027]. The printing head is fixedly connected to the second supporting part 12, and Ji discloses that when the printing platform exerts a force on the printing head during printing, the force is transferred through the printing head to the second supporting part, deforming it relative to the fixing plate and thereby deforming the strain gauge, the resulting change in resistance being converted into a change in voltage by a control circuit so that the main control chip detects the force and the printer controls the printing head to move away from the printing platform, thereby achieving automatic leveling. See Figures 2 and 3 and [0030] and [0031].
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/John J DeRusso/Primary Examiner, Art Unit 1744
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